Yes, lots of people will want it. For the longest time 'none' was fastest, and still is except for some of the newer storage like RBD.
With a little more tinkering you could apply a different setting for block,file,and network storage as they're already split out right there in that file. I worry a tiny bit though that such a feature won't be exposed to end users, and will be a way of boosting performance at the cost of reliability/safety. Users might be aware of the performance but not realize that their cloud provider is running writeback. That's not a reason to not have the feature, of course. On Feb 15, 2013 8:26 AM, "Jason Villalta" <ja...@rubixnet.com> wrote: > Thanks for all your help guys. I am on 4.0 currently. I will go the > agent route and see what I can do. > > As for putting in the feature request. I will do that as well since I > am sure the more people use cloudstack the more people will run into > this. I really thing the UI is far superior experience. > > On a side note, the VLAN stuff needs some better documentation around > configuration with KVM. Is there a place I can add some of my notes > once I get past this disk issue and test everything? > > > On Fri, Feb 15, 2013 at 10:19 AM, Wido den Hollander <w...@widodh.nl> > wrote: > > On 02/15/2013 03:05 PM, Jason Villalta wrote: > >> > >> So is there anyway to make this work today or will I have to wait > >> until this is properly implemented? This may mean I need to take > >> another look at openstack or opennebula and switch back. > >> > > > > No, not today in a release of CloudStack. > > > > What you however can do is download the source and build the agent > plugin. > > Assuming you use 4.0: > > > > $ cd plugins/hypervisor/kvm > > $ nano src/com/cloud/hypervisor/kvm/resource/LibvirtVMDef.java > > $ mvn > > > > Change the "none" setting to what you like. > > > > Now you will have a .jar file in the "target" directory which you use to > > replace the /usr/share/java/cloud-plugin-hypervisor-kvm.jar on your > > production systems. > > > > Wido > > > > > >> On Fri, Feb 15, 2013 at 9:00 AM, Wido den Hollander <w...@widodh.nl> > >> wrote: > >>> > >>> On 02/15/2013 02:31 PM, Jason Villalta wrote: > >>>> > >>>> > >>>> Is there any way easy way to make this setting dependent on the > >>>> storage definition? For example some primary storage may need this > >>>> set to one value such as cache=writeback such as with the case of ZFS, > >>>> GlusterFS, CEPH. Then other storage may want a different setting such > >>>> as cache=writethough or none which is the case with a local ext4 > >>>> storage or NFS. > >>>> > >>> > >>> Exactly. > >>> > >>> I brought this up about a week ago, see this thread: > >>> http://markmail.org/thread/qmrod55gfmhwzot4 > >>> > >>> It shouldn't be a global property, it should be defined per storage > pool, > >>> or > >>> even better, per disk offering. > >>> > >>> Right now we are talking about the cache setting, but tomorrow it could > >>> be a > >>> different setting. > >>> > >>> Wido > >>> > >>> > >>>> > >>>> > >>>> On Thu, Feb 14, 2013 at 11:08 PM, Rajesh Battala > >>>> <rajesh.batt...@citrix.com> wrote: > >>>>> > >>>>> > >>>>> Hi Jason Villalta, > >>>>> In LibvirtVmDef.java, there is DiskDef class , get the cache value > >>>>> from > >>>>> the Global config, while constructing the xml in the override method > >>>>> the > >>>>> class toString() specify the cache value, currently it is using > "none". > >>>>> > >>>>> NOTE: whenever there is change in GC value, MS should restart for the > >>>>> value to take effect. > >>>>> > >>>>> Thanks > >>>>> Rajesh Battala > >>>>> > >>>>>> -----Original Message----- > >>>>>> From: Rajesh Battala [mailto:rajesh.batt...@citrix.com] > >>>>>> Sent: Friday, February 15, 2013 9:22 AM > >>>>>> To: cloudstack-us...@incubator.apache.org; cloudstack- > >>>>>> d...@incubator.apache.org > >>>>>> Subject: RE: Change qcow disk cache=none > >>>>>> > >>>>>> Hi Jason Villalta, > >>>>>> > >>>>>> Can you raise the ticket for the same. I can work on it if you > assign > >>>>>> to > >>>>>> me. > >>>>>> > >>>>>> Thanks > >>>>>> Rajesh Battala > >>>>>> > >>>>>>> -----Original Message----- > >>>>>>> From: Edison Su [mailto:edison...@citrix.com] > >>>>>>> Sent: Friday, February 15, 2013 4:59 AM > >>>>>>> To: cloudstack-us...@incubator.apache.org > >>>>>>> Subject: RE: Change qcow disk cache=none > >>>>>>> > >>>>>>> The code is at > https://git-wip-us.apache.org/repos/asf?p=incubator- > >>>>>>> > >>>>>>> > cloudstack.git;a=blob;f=plugins/hypervisors/kvm/src/com/cloud/hypervis > >>>>>>> or/kv > >>>>>>> > >>>>>> > m/resource/LibvirtVMDef.java;h=acfd9cf1fe8eba217f09e20adf3101d1295d51d > >>>>>>> > >>>>>>> > >>>>>>> a;hb=HEAD, search "cache". > >>>>>>> you can add a global configuration in cloudstack, or add a > >>>>>>> configuration in agent.properties, to specify cache attribute. > >>>>>>> > >>>>>>>> -----Original Message----- > >>>>>>>> From: Jason Villalta [mailto:ja...@rubixnet.com] > >>>>>>>> Sent: Thursday, February 14, 2013 2:16 PM > >>>>>>>> To: cloudstack-us...@incubator.apache.org > >>>>>>>> Subject: Re: Change qcow disk cache=none > >>>>>>>> > >>>>>>>> Ok, I see the folks at openstack ran into a similar issue. > >>>>>>>> https://bugs.launchpad.net/nova/+bug/959637 > >>>>>>>> > >>>>>>>> How can I contribute to this? Can you recommend a part of the > code > >>>>>>>> to look at so I can build and test a patch? > >>>>>>>> > >>>>>>>> On Thu, Feb 14, 2013 at 5:13 PM, Edison Su <edison...@citrix.com> > >>>>>>>> wrote: > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> need to change cloudstack java code, right now, it's hard coded > to > >>>>>>>> > >>>>>>>> > >>>>>>>> "cache=none". > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> > >>>>>>>>>> -----Original Message----- > >>>>>>>>>> From: Jason Villalta [mailto:ja...@rubixnet.com] > >>>>>>>>>> Sent: Thursday, February 14, 2013 1:45 PM > >>>>>>>>>> To: cloudstack-us...@incubator.apache.org > >>>>>>>>>> Subject: Change qcow disk cache=none > >>>>>>>>>> > >>>>>>>>>> Is there a way to change this kvm disk cache setting in > >>>>>>>>>> Cloudstack or > >>>>>>>> > >>>>>>>> > >>>>>>>> template? > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>>> If so where is the setting applied? > >>>>>>>>>> > >>>>>>>>>> -- > >>>>>>>>>> -- > >>>>>>>>>> Jason Villalta > >>>>>>>>>> Co-founder > >>>>>>>>>> 800.799.4407 | www.RubixTechnology.com > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> -- > >>>>>>>> -- > >>>>>>>> Jason Villalta > >>>>>>>> Co-founder > >>>>>>>> 800.799.4407 | www.RubixTechnology.com > >>>> > >>>> > >>>> > >>>> > >>>> > >>> > >> > >> > >> > > > > > > -- > -- > Jason Villalta > Co-founder > 800.799.4407 | www.RubixTechnology.com >
